Continuation of support is requested for research analyzing how membranes engage in specific recognition, adhesion, and disadhesion during the mating reaction of Chlamydomonas reinhardi. Identification of the (glyco)polypeptides that participate in these events will be sought using detergent-solubilized flagella and bioassays that capitalize on known features of the association and adhesion phenomena. Nonagglutinating mutant strains and zygotic cells will be used as controls. Candidate macromolecules will be analyzed by standard protein biochemistry and immunological procedures, the ultimate goal being to learn how the membranes of the two mating types so differ that they can engage in complementary associations with one another.